Apparatus and method for crimping yarn



Feb. 2, 19165 K; [WNECKE ETAL APPARATUS AND Mamw mm CHEWING? mm Filed Aug. 29?, 1962 Inventor Attorneys F k M IK ur .m M 5 1 v m WU Km Kurt Iwnicki, Ponthir, and

Pontypool, England Filed Aug. 29, 1962, Ser. No. 220,289 Claims priority, application Great Britain, Sept. 14, 1961,

4 4 Claims. c1. 28-1) The present invention concerns improvements in or relating to the crimping of yarn and has particular reference to crimping by the so-called stutter-box process. As is now well-known, the crimping of yarns is often desirable in order to increase their bulk and to give them a fuller and loftier handle than that which they posses in uncrimped form. Crimping has become one of the major processes in the field of yarn supply and, although it is sometimes carried out on yarns or slivers of staple fibre, it is normally carried out on continuous filament yarns and it has enabled them to be utilized in many textile articles in which traditionally only spun yarns were capable of being used. Such textile articles are for example knitted outerwear and carpets, whether the latter be of the cut or uncut pile type.

One of the now well-established crimping processes, for both spun staple yarns and continuous filament yarns, is the stutter-box process above referred to, with which this invention is particularly concerned. In this process, which in its essentials dates back some fifty years, yarn is forced by feed rolls into a crimping chamber comprising a zone of compression in which a predetermined back-pressure is maintained, and the yarn is therein crimped and compacted. The yarn may either be forced out of the stutter-box or be pulled out under tension, the latter method of removal providing a finer control over the process and hence of the characteristics of the crimped yarn, and enabling the process to be one in which yarn starts in a package and ends up in a package in a continuous manner.

It is sometimes possible for part or all of a filamentary structure to slip slightly between the rolls when the latter are being used to withdraw the filamentary structure from a supply or supplies thereof; and this is especially the case when, as is often desirable, there is a small clearance between the peripheries of the feed rolls at their closest point. Consequently, separate feed means are sometimes employed whose function is to withdraw the filamentary structure from its supply and to forward it to the feed rolls of the stuffer-box at a low tension when the risk of slipping will be greatly minimised if not completely obviated. The disadvantage of slipping may only be likely to be of great consequence when the filamentary structure being crimped comprises a plurality of multi-filarnent yarns and the slipping affects one or more of such yarns. In that event the composite crimped yarn withdrawn from the stuffer-box will comprise component yarns which have had an unequal crimp; and one effect of such unequal crimping will be that the composite yarn has a tendency to split up into its separate components, when employed, for example, as pile yarn in a tufted carpet. This splitting of the yarn into its components may not be desirable.

We have now found that a most convenient and effective means for forwarding a filamentary structure to a stutter-box crimper automatically at the correct rate and under a low, even or a negligible tension is provided by apparatus comprising rotatable forwarding means driven by contact with one of the feed rolls of the stufferbox, the filamentary structure being led at least partly around such means and between it and the feed roll vUnited States Patent ICC prior to its entry between the nip of the feed rolls of the stuffer-box.

Accordingly the invention consists in a stutter-box crimper comprising feed rolls for forcing a filamentary structure therebetween and into a zone of compression, and having rotatable means for forwarding the filamentary structure to said feed rolls, which rotatable means is driven by contact with one of the said feed rolls, so that the filamentary structure is automatically and positively forwarded to the feed rolls at the same rate that it is forced into the zone of compression. The invention also consists in a process for crimping a filamentary structure comprising positively forwarding said structure automatically at the desired rate, and at a low, even or a negligable tension, to the feed rolls of a stuifer-box crimper, and crimping the structure therein.

Preferably the forwarding means comprises a roll driven byperipheral contact with the stuifer-box feed roll and held in contact therewith by a spring or other like means. Preferably, also, such a driven roll has a peripheral surface composed of a material, such as rubber, having a high coeflicient friction with the filamentary structure in order that the forwarding effect shall be a positive one.

The invention will now be described with reference to the accompanying drawing which is a diagrammatic side view of a stutter-box crimper and forwarding means according to one convenient embodiment of the invention.

The stutter-box crimper shown diagrammatically at 1 has driven feed rolls 3 and 5, whose peripheries are at their closest point some 3 thousandths of an inch apart, for forcing the filamentary structure 7 into the zone of compression within the stutter-box where the structure, in this case a single yarn, is crimped. Bearing against the periphery of feed roll 5, and pivoted about a point in the vertical plane of the nip of the feed rolls, is forwarding roll 9 having a point of contact with the periphery of feed roll 5 some of arc clockwise from the nip of the feed rolls 3 and 5. The forwarding roll 9 has a peripheral surface of rubber, and is held in contact with feed roll 5 by means of spring 11 which is attached at one of its ends to an extension of arm 13 on which roll 9 is mounted, and at the other of its ends to a portion of the machine mounting. Yarn 7 is led through guide 15 from a source of supply (not shown) and thence travels in contact with a portion of the periphery of roll 9 before being forwarded from the nip of rolls 5 and 9 at a low tension to the stutter box. The yarn may then travel continuously in contact with the portion of the periphery of roll 5 prior to entry into the stutter-box, or it may intermittently be raised slightly clear thereof in a free loop, depending on whether there is any slippage between it and the rolls 3 and 5.

It will be seen, therefore, that according to the invention a means is provided for forwarding a filamentary structure, whether composed of a single or a plurality of component yarns or filaments, to a stulfer-box under a low, even or a negligible tension, such means being of a kind that automatically provides for the correct for warding rate, owing to the fact that it is driven by contact with one of the feed rolls itself.

We claim:

1. Apparatus for crimping a continuous filamentary structure comprising: a crimping chamber; two fixed closely-spaced feed rolls driven at a predetermined rate such that said structure when passed between them is forced into said chamber; and structure forwarding means comprising a third roll arranged so that said structure is in contact with a portion of the periphery of said third roll and is gripped between said third roll and one of said feed rolls, said third roll being driven by said one 3 4 feedroll such-that said structure is positively forwarded 4.'A process according to claim 3 wherein the strucby said third roll at the sarne rate as said predetermined ture is withdrawn from its supply and is forwarded to rate at which it is forced into said chamber. the feed rolls by being passed between the nip of a roll 2. Apparatus according to claim '1, wherein said third held in driven contact with the periphery of one of roll has a peripheral surfaceof a material which .has a 5 the said feed rolls. high coefiicient of friction with the filamentary structure.

3. A process for crimping ,a continuousfilamentary. References Cited .by the Examiner structure comprising the steps of UN T S A PA E T (a) positively withdrawing said structure from a supply thereof at a predetermined rate, 10 g. ;i"f 3 ([2) forwarding said structure at said rate to a pairv Sh a 1 a u of driven feed rolls, 3,00 0 r alttuck et 28 72 (c) forcing said structure between the nip of said 3022545 2/6 Wy de et 28 72 feed rolls intoa zone of compression, (d) resisting the emergence of said structure from said 15 FOREIGN zone in order to crimp same therein, and 2301339 9/ 60 Austrflha- (e) automatically positively maintaining the said prev determined rate the same as the rate at which said DONALD PI-1mm}; Exammer' structureis forced into said zone-of compression. RUSSELL ,C. MADER, :MERVIN .STEIN, Examiners. 

1. APPARATUS FOR CRIMPING A CONTINUOUS FILAMENTARY STRUCTURE COMPRISING: A CRIMPING CHAMBER; TWO FIXED CLOSELY-SPACED FEED ROLLS DRIVEN AT A PREDETERMINED RATE SUCH THAT SAID STRUCTURE WHEN PASSED BETWEEN THEM IS FORCED INTO SAID CHAMBER; AND STRUCTURE FORWARDING MEANS COMPRISING A THIRD ROLL ARRANGED TO THAT SAID STRUCTURE IS IN CONTACT WITH A PORTION OF THE PERIPHERY OF SAID THIRD ROLL AND IS GRIPPED BETWEEN SAID THIRD ROLL AND ONE OF SAID FEED ROLLS, SAID THIRD ROLL BEING DRIVEN BY SAID ONE FEED ROLL SUCH THAT SAID STRUCTURE IS POSITVELY FORWARDED BY SAID THIRD ROLL AT THE SAME RATE AS SAID PREDETERMINED RATE AT WHICH IT IS FORMED INTO SAID CHAMBER. 